1. Field of the Invention
The present invention relates generally to vehicles and air conditioning systems for use in such vehicles. In particular, the present invention is directed towards vehicles and air conditioning systems in which a compressor of the air conditioning system may be inactive, but a blower of the air conditioning system may be active, during vehicle operation.
2. Description of Related Art
Known hybrid vehicles include a first drive source, e.g., an engine, a second drive source, e.g., an electric motor, and an air conditioning system. The air conditioning system includes a compressor and a blower. The blower dispenses air into an interior of the vehicle. For example, the blower dispenses cooled air into the interior of the vehicle when a driver of the vehicle signals to decrease a temperature within the vehicle from an measured temperature to a first predetermined temperature which is less than the measured temperature. Similarly, the blower dispenses heated air into the interior of the vehicle when a driver of the vehicle signals to increase a temperature within the vehicle from the measured temperature to a second predetermined temperature which is greater than the measured temperature. Moreover, the first drive source and the second drive source drive the vehicle, the compressor, and the blower. When the driver of the vehicle activates an ignition of the vehicle, a vehicle operation commences. In such known vehicles, when the vehicle is stationary during vehicle operation, e.g., when the driver of the vehicle stops the vehicle at a stop sign, a red light, or the like, and predetermined conditions are satisfied, the compressor transitions from active to inactive, i.e., the compressor is deactivated. Moreover, when the compressor transitions from active to inactive, the blower also transitions from active to inactive.
Nevertheless, when the blower is inactive, air is not dispensed into the interior of the vehicle from the air conditioning system. Consequently, after the blower transitions from active to inactive, a temperature of air within the interior of the vehicle increases or decreases. Whether the temperature of air within the interior of the vehicle increases or decreases depends on whether the driver previously signaled for the air conditioning system to dispense cooled air or heated air. Specifically, when the driver previously signaled for the air conditioning system to dispense cooled air, the temperature of air within the interior of the vehicle increases. Similarly, when the driver previously signaled for the air conditioning system to dispense heated air, the temperature of air within the interior of the vehicle decreases.
Therefore, a need has arisen for vehicles and air conditioning systems which overcome these and other short comings of the related art. A technical advantage of the present invention is that when the compressor transitions from active to inactive during vehicle operation, the blower remains active. Consequently, a rate at which the temperature of air within the vehicle increases or decreases after the compressor transitions from active to inactive is less than in the known vehicles and air conditioning systems.
In an embodiment of the present invention, an air conditioning system for a vehicle comprises at least one compressor driven by a first drive source or a second drive source, or a combination thereof, and an evaporator operationally connected to the at least one compressor via a refrigerant circuit. For example, the first drive source and the second drive source may simultaneously or selectively drive the at least one compressor. The system also comprises a blower for dispensing air into an interior of the vehicle via the evaporator. The blower is driven by the first drive source or the second drive source, or a combination thereof. For example, the first drive source and the second drive source may simultaneously or selectively drive the blower. Further, the system comprises means for controlling the first drive source and the second drive source, e.g., a controller.
Specifically, when a temperature of air dispensed from the evaporator is greater than a first predetermined temperature and a speed of the vehicle is greater than a predetermined speed, the first drive source drives the at least one compressor and the blower. Moreover, when the temperature of air dispensed from the evaporator is greater than a second predetermined temperature, the speed of the vehicle is less than the predetermined speed, and a voltage of a power source of the second drive source is less than or equal to a predetermined voltage, the at least one compressor is inactive and the second drive source drives the blower. For example, the first predetermined temperature may be about the same as the second predetermined temperature. In another embodiment, when the temperature of air dispensed from the evaporator is greater than the second predetermined temperature, the speed of the vehicle is less than the predetermined speed, and the voltage of the power source is greater than the predetermined voltage, the second drive source drives the blower and the at least one compressor. Moreover, the first drive source or the second drive source, or a combination thereof, may drive the vehicle. For example, the first drive source and the second drive source may selectively or simultaneously drive the vehicle, e.g., in a hybrid vehicle, or only the first drive source may drive the vehicle, e.g., in a non-hybrid vehicle.
In another embodiment of the present invention, a vehicle comprises a first drive source, a second drive source, and an air conditioning system. The air conditioning system comprises at least one compressor driven by a first drive source or a second drive source, or a combination thereof, and an evaporator operationally connected to the at least one compressor via a refrigerant circuit. For example, the first drive source and the second drive source may simultaneously or selectively drive the at least one compressor. The system also comprises a blower for dispensing air into an interior of the vehicle via the evaporator. The blower is driven by the first drive source or the second drive source, or a combination thereof For example, the first drive source and the second drive source may simultaneously or selectively drive the blower. Further, the system comprises means for controlling the first drive source and the second drive source, e.g., a controller. Specifically, when a temperature of air dispensed from the evaporator is greater than a first predetermined temperature and a speed of the vehicle is greater than a predetermined speed, the first drive source drives the at least one compressor and the blower. Moreover, when the temperature of air dispensed from the evaporator is greater than a second predetermined temperature, the speed of the vehicle is less than the predetermined speed, and a voltage of a power source of the second drive source is less than or equal to a predetermined voltage, the at least one compressor is inactive and the second drive source drives the blower.
In another embodiment of the present invention, a method of controlling an air conditioning system for a vehicle comprises the step of driving at least one compressor and a blower via a first drive source, when a temperature of air dispensed from an evaporator is greater than a first predetermined temperature and a speed of the vehicle is greater than a predetermined speed. The method also comprises the step of deactivating the at least one compressor and driving the blower via a second drive source when the temperature of air dispensed from the evaporator is greater than a second predetermined temperature, the speed of the vehicle is less than the predetermined speed, and a voltage of a power source of the second drive source is less than or equal to a predetermined voltage.
Other objects, features, and advantage will be apparent to persons of ordinary skill in the art from the following detailed description of the invention and the accompanying drawings.